f Methanohalophilus mahii gen. nov., sp. nov., a Methylotrophic Halophilic Methanogen †

A new genus of methanogenic bacteria (Methanohalophilus) comprising a single species, Methanohalophilus mahii sp. nov., is described. The microorganisms of this genus require sodium chloride concentrations in the moderately halophilic range of 1.0 to 2.5 M for optimal growth and methanogenesis. Methanol and methylamines are the substrates that are utilized for growth. M. mahii is a methanogenic coccoid microorganism isolated from the sediments of the Great Salt Lake. The optimum temperature and salinity for growth and methanogenesis were 37°C and 2.0 M NaCI, respectively. The description is based on a single strain, strain SLP (= ATCC 35705), which is thus the type strain.